Syria’s chaos is growing, with increased fighting among the opposition groups and fresh evidence that Bashar al-Assad is again using chemical weapons. But the chaos of US Syria policy is growing too, with the news that the administration is now supplying the rebels advanced weapons.

Chaos is not a good answer to chaos. By vacillating for three years on whether to arm “moderate” opposition forces, by failing to uphold his “red line” on chemical weapons and by indulging in rhetoric unaccompanied by action, President Obama has helped produce the worst of all possible outcomes.

When the Arab Spring erupted and Assad’s opponents took to the streets, many in Washington believed he would fall quickly. When Assad cracked down and armed conflict ensued, those same observers predicted his rapid defeat. When Assad fought back ruthlessly, the observers called for arming the rebels. When the rebels became increasingly dominated by al Qaeda and other terrorist groups, the observers went largely silent.

By contrast, Obama consistently ordered that aid to Syria’s opposition be either humanitarian, or confined to training and advising rather than equipping rebels with lethal weaponry. His advisers argued repeatedly that Russia would be an active, willing partner in negotiating a peaceful transition, replacing Assad with representative government.

But Obama and rebel supporters alike have consistently misunderstood what’s actually going on. The risk was always high that the opposition would be dominated by the Moslem Brotherhood at best, if not by outright terrorists like al Qaeda. After decades of Ba’ath party repression, there was as little chance of finding Jeffersonian democrats waiting to take over in Damascus as in Baghdad after Saddam Hussein’s fall. There were too many scores to settle — political, religious, ethnic and more.

And it was delusional from the start to think we had anything like common interests with Russia. Why would Moscow willingly help depose its sole Arab ally and risk losing the naval base at Tartus, its only military facility outside the former Soviet Union?

Even more mystifying was Obama’s unwillingness to acknowledge the underlying reality in Syria: Assad has long been effectively a satellite of Tehran, a key component in its regional arc of Shia influence, including Iraq’s al-Maliki government and Hezbollah in Lebanon. Obama either refused to see Tehran’s dominance or feared to confront it, worried that his prized negotiations over Iran’s nuclear program would be a casualty of any effort to oust Iran’s henchman in Damascus.

Now Obama is apparently shifting from one erroneous policy to another, arming a new “moderate” opposition group. Yet neither side in Syria’s ongoing chaos could possibly merit Washington’s military support. The choice of Iran’s mullahs or al Qaeda’s emirs is a classic case where we should hope both sides lose.

Instead, an effective US Middle East policy must recognize that, tragic though it’s been, the conflict in Syria is a strategic sideshow. The real threats to the United States come not from those directly engaged in that fighting, but from their patrons and larger incarnations.

Thus, the Assad regime, loathsome as it is, couldn’t survive without substantial Iranian assistance. And it is Iran, through its pursuit of nuclear weapons and its decades-long role as international terrorism’s central banker, which poses the central danger.

Instead of focusing on overthrowing Assad or aiding his enemies, we should be vigorously pursuing regime change in Iran. As Alexander Haig once put it, “go to the source.”

Obama, by contrast, is doing very nearly the opposite. By negotiating with Iran, he has not only allowed it a path to legitimize its nuclear-weapons program, but objectively facilitated the deadly global menace in Tehran.

Some will concede that a victory by Syria’s rebels is likely to replace Assad with terrorists, but nonetheless worry that al Qaeda is capitalizing on US inaction, using Syria to recruit new adherents. Yet Washington’s ability to affect the outcome in Syria is decidedly limited; aiding the rebels mainly increases the chances of an al Qaeda regime in Damascus — hardly preferable to the current bloodshed.

In short, Washington must focus on the real threats, neither minimizing nor dismissing them, and not be distracted by Syria’s conflict. We can only hope, contrary to the available evidence, that the collapse of the Syrian “peace” negotiations, Russia’s continuing perfidy in Ukraine and elsewhere and Iran’s unrelenting pursuit of nuclear weapons may yet awaken our president from dreamland.